Businesses often use data as the basis for business decisions. A business decision can rely on structured data, such as data stored in a relational database. Other data can be used in business decision making, such as unstructured data from heterogeneous sources, such as in the form of XML (eXtensible Markup Language), text, PDF (Portable Document Format), audio and video.
Histories of different versions of data items can be stored. Having access to historical versions of data items can assist in the analysis and interpretation of data. For example, examining historical versions of data items can assist in analyzing the quality, timeliness, reliability, and volatility of data, to name a few examples. In addition, having access to prior versions of a data item can allow for the “rolling back” of a data item to a previous version, such as if an error in data processing is discovered.